The U.S. nuclear industry must do more to ensure the safety of spent fuel pools during extreme events and severe accidents to avoid another nuclear disaster similar to what happened in Japan in 2011, according to a new study funded by the U.S. Nuclear Regulatory Commission (NRC).
The National Academies of Sciences, Engineering, and Medicine found that plant operators needed to improve the ability to measure real-time conditions in spent fuel pools and maintain adequate cooling of stored spent fuel during accidents and terrorist attacks. The improvements need to go beyond the post-Fukushima implemented safeguards to include hardened and redundant physical surveillance systems such as cameras, radiation monitors, pool temperature and water-level monitors, and means to deliver makeup water or sprays to the pools, even when physical access is limited by facility damage or high radiation levels.
Phase 1 of the study, released in July 2014, focused on the causes of the accident at the Fukushima Daiichi nuclear plant and lessons learned to improve U.S. nuclear plant operations, systems and regulations exclusive of spent fuel storage. In the recently released second phase, the report highlights that the industry and the NRC has implemented many of the recommendations from previous reports on spent fuel safety and security with the exception of two: to analyze the vulnerabilities of spent fuel pools to specific terrorist attack scenarios describe in the 2004 Academies report, and to carry out an independent examination of surveillance and security measures for protecting stored spent fuel. The independent examination should address the effectiveness of the NRC’s security and surveillance measures for addressing the insider threat. The committee also recommended that the NRC and industry strengthen their capabilities for identifying, evaluating, and managing the risks from terrorist attacks and that the NRC sponsor a spent fuel storage security risk assessment of sufficient scope and depth to explore the benefits of the methodology for enhancing security at U.S. nuclear plants.
Though these analyses are valuable technical contributions to understanding the consequences of spent fuel pool accidents, they are of limited use for assessing spent fuel storage risks because they do not consider the risks of sabotage or dry cask storage, or certain health consequences that could result from a severe nuclear accident. It is also difficult to make comparisons between pool and dry cask storage risks because of the way the analyses were carried out. The committee recommended that the NRC perform a spent fuel storage risk assessment that addresses both accident and sabotage risks for both pool and dry cask storage.
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